A microelectromechanical system (MEMS) typically has mechanical structures formed in a semiconductor substrate using conventional semiconductor processing techniques. A MEMS can include a single structure or multiple structures. MEMS have an electrical component, where an electrical signal activates each or is produced by actuation of each structure in a MEMS.
MEMS can be formed by laminating a series of layers, where one or more of the layers include apertures or recesses. Alternatively, MEMS can be formed by successive deposition and etching processes. Combinations of laminating and deposition and etching processes can also be used. Some MEMS include a series of repeating structures. Typically, it is desirable to be able to form reproducibly uniform features for each repeating structure. Reproducibility can depend in part on stable processing conditions.
A series of MEMS containing dies can be formed on a single substrate. Once the features that form the MEMS are completed, the dies can be released from the substrate, such as by sawing the substrate into the individual dies. Alternatively, streets or kerfs can be etched into one or both sides of the substrate and the dies can be manually broken off by snapping the substrate along the streets or kerfs. As shown in FIG. 1, this method often leaves damage on the edge of the die 10, such as chips 20, for example, areas where a piece or fragment is missing, rough edges or burrs 30 of excess material. This damage can be removed, if required, by polishing. However, polishing can create slag or other debris. Therefore, the chips, microcracks or burrs are typically left on the diced edges.